A sticker-like patch that changes color when exposed to the high pressures from a bomb blast could provide an instant visual cue to soldiers and battlefield medics about how serious a resulting injury from the blast might be.

Researchers at the University of Pennsylvania designed the patches to be worn on parts of a soldier's uniform that cover sensitive body areas, like the helmet. When exposed to a blast shock wave, the color intensity of the patch decreases. In the photo above, the top row (a, b, and c) gives examples of the patch color before a blast, the bottom row (d, e, and f) shows how the color would change after sustaining damage.

So, if a soldier suffers a major brain injury from blast-exposure, a medic will know instantly just how serious the damage is to the affected area. In hostile battlegrounds like Iraq and Afghanistan, even the short amount of time it takes to assess a soldier's wounds can make the difference between life and death.

The patch is made of microscopic crystals, according to Tech News Daily, whose geometry can be manipulated to control the way it interacts with light. As soon as the crystals shatter, the color changes. 

But this technology won't be on the battlefield any time soon. The study's co-author, Shu Yang, told Tech News Daily that more work was needed “to model the relationship between structure change, color change and blast force and time." She said these color-changing patches won't have a commercial use for at least another decade.

The researchers detailed their findings online in the journal NeuroImage.

Photos: Courtesy Douglas H. Smith and Shu Yang, University of Pennsylvania